Water glass casting (sodium silicate casting) is a technology of Russian origin. This technology is mostly used for steel and stainless steel components. By using this technique more complex designs can be made compared to the sand casting technique. Pricewise it is for big size products more interesting, compared to silica sol castings, however less precise in dimensions.
Water glass (sodium silicate) is used to cure the ceramic layers. This substance is added to the slurry. The wax tree is then immersed (in the slurry). The slurry continues to adhere to the wax, after which it is strewed with ceramics. It is then placed in a bath with a water chloride solution. The water glass (adhering to the wax with the slurry) reacts to this solution in the bath, thereby curing the layer. This layering process is repeated a number of times until the layer is sufficiently thick enough for pouring. If necessary, a smoother casting surface can be achieved by using the first ceramic layers as it is used in the silica sol technique. Only it will take longer to make the shell.
Water glass cast components are mainly used where heavier/stronger and yet more complex shapes are required. Applications of this technique are widely presented in production of trailers, agricultural machineries and in offshore industry.